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                  <a href="#gnome-vfs-2.0-gnome-vfs-cancellation.description" class="shortcut">Description</a>
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<a name="gnome-vfs-2.0-gnome-vfs-cancellation"></a><div class="titlepage"></div>
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<h2><span class="refentrytitle"><a name="gnome-vfs-2.0-gnome-vfs-cancellation.top_of_page"></a>Cancellation</span></h2>
<p>Cancellation — halt in-progress operations</p>
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<a name="gnome-vfs-2.0-gnome-vfs-cancellation.synopsis"></a><h2>Synopsis</h2>
<pre class="synopsis"><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="returnvalue">GnomeVFSCancellation</span></a> * <a class="link" href="gnome-vfs-2.0-gnome-vfs-cancellation.html#gnome-vfs-cancellation-new" title="gnome_vfs_cancellation_new ()">gnome_vfs_cancellation_new</a>       (<em class="parameter"><code><span class="type">void</span></code></em>);
<span class="returnvalue">void</span>                <a class="link" href="gnome-vfs-2.0-gnome-vfs-cancellation.html#gnome-vfs-cancellation-destroy" title="gnome_vfs_cancellation_destroy ()">gnome_vfs_cancellation_destroy</a>      (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);
<span class="returnvalue">void</span>                <a class="link" href="gnome-vfs-2.0-gnome-vfs-cancellation.html#gnome-vfs-cancellation-cancel" title="gnome_vfs_cancellation_cancel ()">gnome_vfs_cancellation_cancel</a>       (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);
<span class="returnvalue">gboolean</span>            <a class="link" href="gnome-vfs-2.0-gnome-vfs-cancellation.html#gnome-vfs-cancellation-check" title="gnome_vfs_cancellation_check ()">gnome_vfs_cancellation_check</a>        (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);
<span class="returnvalue">void</span>                <a class="link" href="gnome-vfs-2.0-gnome-vfs-cancellation.html#gnome-vfs-cancellation-ack" title="gnome_vfs_cancellation_ack ()">gnome_vfs_cancellation_ack</a>          (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);
<span class="returnvalue">gint</span>                <a class="link" href="gnome-vfs-2.0-gnome-vfs-cancellation.html#gnome-vfs-cancellation-get-fd" title="gnome_vfs_cancellation_get_fd ()">gnome_vfs_cancellation_get_fd</a>       (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);
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<a name="gnome-vfs-2.0-gnome-vfs-cancellation.description"></a><h2>Description</h2>
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<a name="gnome-vfs-2.0-gnome-vfs-cancellation.details"></a><h2>Details</h2>
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<a name="gnome-vfs-cancellation-new"></a><h3>gnome_vfs_cancellation_new ()</h3>
<pre class="programlisting"><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="returnvalue">GnomeVFSCancellation</span></a> * gnome_vfs_cancellation_new       (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>
Create a new <a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> object for reporting cancellation to a
gnome-vfs module.
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<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> A pointer to the new GnomeVFSCancellation object.
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<a name="gnome-vfs-cancellation-destroy"></a><h3>gnome_vfs_cancellation_destroy ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>                gnome_vfs_cancellation_destroy      (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);</pre>
<p>
Destroy <em class="parameter"><code>cancellation</code></em>.
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<td><p><span class="term"><em class="parameter"><code>cancellation</code></em> :</span></p></td>
<td>a <a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> object.
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<a name="gnome-vfs-cancellation-cancel"></a><h3>gnome_vfs_cancellation_cancel ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>                gnome_vfs_cancellation_cancel       (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);</pre>
<p>
Send a cancellation request through <em class="parameter"><code>cancellation</code></em>.
</p>
<p>
If called on a different thread than the one handling idle
callbacks, there is a small race condition where the
operation finished callback will be called even if you
cancelled the operation. Its the apps responsibility
to handle this. See <a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#gnome-vfs-async-cancel" title="gnome_vfs_async_cancel ()"><code class="function">gnome_vfs_async_cancel()</code></a> for more
discussion about this.
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<td><p><span class="term"><em class="parameter"><code>cancellation</code></em> :</span></p></td>
<td>a <a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> object.
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<a name="gnome-vfs-cancellation-check"></a><h3>gnome_vfs_cancellation_check ()</h3>
<pre class="programlisting"><span class="returnvalue">gboolean</span>            gnome_vfs_cancellation_check        (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);</pre>
<p>
Check for pending cancellation.
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<td><p><span class="term"><em class="parameter"><code>cancellation</code></em> :</span></p></td>
<td>a <a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> object.
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<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> <code class="literal">TRUE</code> if the operation should be interrupted.
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<a name="gnome-vfs-cancellation-ack"></a><h3>gnome_vfs_cancellation_ack ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>                gnome_vfs_cancellation_ack          (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);</pre>
<p>
Acknowledge a cancellation.  This should be called if
<a class="link" href="gnome-vfs-2.0-gnome-vfs-cancellation.html#gnome-vfs-cancellation-check" title="gnome_vfs_cancellation_check ()"><code class="function">gnome_vfs_cancellation_check()</code></a> returns <code class="literal">TRUE</code> or if <code class="function">select()</code> reports that
input is available on the file descriptor returned by
<a class="link" href="gnome-vfs-2.0-gnome-vfs-cancellation.html#gnome-vfs-cancellation-get-fd" title="gnome_vfs_cancellation_get_fd ()"><code class="function">gnome_vfs_cancellation_get_fd()</code></a>.
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<td><p><span class="term"><em class="parameter"><code>cancellation</code></em> :</span></p></td>
<td>a <a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> object.
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<a name="gnome-vfs-cancellation-get-fd"></a><h3>gnome_vfs_cancellation_get_fd ()</h3>
<pre class="programlisting"><span class="returnvalue">gint</span>                gnome_vfs_cancellation_get_fd       (<em class="parameter"><code><a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> *cancellation</code></em>);</pre>
<p>
Get a file descriptor -based notificator for <em class="parameter"><code>cancellation</code></em>.  When
<em class="parameter"><code>cancellation</code></em> receives a cancellation request, a character will be made
available on the returned file descriptor for input.
</p>
<p>
This is very useful for detecting cancellation during I/O operations: you
can use the <code class="function">select()</code> call to check for available input/output on the file
you are reading/writing, and on the notificator's file descriptor at the
same time.  If a data is available on the notificator's file descriptor, you
know you have to cancel the read/write operation.
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<td><p><span class="term"><em class="parameter"><code>cancellation</code></em> :</span></p></td>
<td>a <a class="link" href="gnome-vfs-2.0-gnome-vfs-async-ops.html#GnomeVFSCancellation" title="GnomeVFSCancellation"><span class="type">GnomeVFSCancellation</span></a> object.
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<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> the notificator's file descriptor, or -1 if starved of
              file descriptors.
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